How to prepare thymolphthalein indicator?
👉How to prepare thymolphthalein indicator?
👉Thymolpthalein is to substitute use of phenolothalein indicator..
👉but normal VA still use methyl orange
👉It will be clear in acid and blue in alkaline. End pt will be clear. Very difficult to determine end point cos colour change is almost the same as in acid.
👉If end point is clear... doesn't it means that the solution is too acidic? 🤔 end point should be light blue right? I mean when phenolpthalein was still in use, end point was light pink
👉Juz to make sure... this is something new
👉Yes light blue. at least better than methyl orange... orange to reddish orange almost cannot tell
👆This morning really hard to see from red to orange
👉Must compare side by side then can see the difference😂
👉The red is too acidic 😂 should be closer to orange
👉Juz 1 drop only make a huge difference
👉Methyl orange is juz plain poor pH indicator. Can understand why MOE needed a better indicator 😂
👉Then without realising turn yellow😂
👉some teachers prefer screen methyl orange
👉where to store them?
👉Put in amber dropping bottle. Usually made fresh just for 2-3 classes.
👉How long can the indicator last?
👉Can last for a week
